The present invention relates to self securing theft proof chain binders. This binder includes two half portions hinged in the middle which are attached at their extremities remote from the hinged portion to chains which are used to secure tightly the load of merchandise as by girdling typically to some sort of truck bed. The ends of the chain are attached off center of the two halves so that when the halves are squeezed together there is a tightning action on the ends of the chain. The lever arm or the binder in this case has a projecting spur which is rounded at its end and has a notch on one side which mates with a lock bolt on the other half of the binder in such a manner that when the two halves are squeezed together, the spur enters into a spring urged latch forming part of the lock. This automatically secures the two halves of the binder and therefore the chain cannot arbitrarily be removed. Further, an eyelet provided on a cable sling can extend over the spur which is then locked. The ensuing detailed description provides variations and improvements over binders currently held by the applicant U.S. Pat. No. 3,974,688 and U.S. Pat. No. 4,062,206. The earlier patent specifies that the lock be fastened to the first swivel which in turn is fastened to a fitting. The later patent specifies that the keeper disc mounted in the keeper link has a conical bolt opening therethrough and further that the lock boss be conical.